The refined SX4 is based on the bullet proof Active Valve System that was the core foundation of the acclaimed SX3. We built on that solid operating mechanism and improved the balance controls and internal operating components of the SX4 to make it a worthy successor to the SX3. Includes three Invector choke tubes full modified and improved cylinder and sling swivel studs. SX4 HYB HNTR 12/26 RTL 3.5" #